Recently, with an advance in digital signal processing techniques, a large amount of digital information such as moving image information, still image information, and sound information can be efficiently coded to be recorded on compact magnetic media and transmitted to communication media. Image sensing apparatuses capable of easily sensing high-quality pictures and quickly outputting the resultant information to information media by using such techniques have been developed.
FIG. 20 shows an example of the arrangement of a conventional image sensing apparatus having a character/graphic pattern synthesizing function. Referring to FIG. 20, reference numeral 901 denotes an image sensing unit; 902, a synthesizing unit; 903, a recording unit; 904, a character/graphic pattern generating unit; and 905, a control unit.
The operation of the image sensing apparatus having the above arrangement will be described.
First of all, the image sensing unit 901 generates a video signal by image-sensing an object and supplies it to the synthesizing unit 902. The control unit 905 supplies the identification numbers of a character and graphic pattern to be synthesized to the character/graphic pattern generating unit 904 in accordance with an instruction from a user. The character/graphic pattern generating unit 904 generates character and graphic pattern raster data in accordance with the supplied identification numbers, and supplies the data to the synthesizing unit 902. The synthesizing unit 902 generates a video signal by superimposing the character and graphic pattern raster data supplied from the character/graphic pattern generating unit 904 on the video signal supplied from the image sensing unit 901, and supplies the signal to the recording unit 903. The recording unit 903 records the video signal, supplied from the synthesizing unit 902, on an information medium. In general, a video signal has an enormous amount of data, and hence is often recorded on a recording medium after being data-compressed by a high-efficiency coding technique using discrete cosine transform or the like.
In the prior art described above, only simple character/graphic pattern synthesis can be performed in accordance with an instruction from the user. It is therefore difficult to provide special effects that entertain a user and a person who is image-sensed. To realize relatively sophisticated special effects by frequently switching characters and graphic patterns, the user must perform complicate operation.